.a{
	background: url('../imgs/背景2.jpg');
	height: 900px;
	width: 100%;
}
.banner {
	margin-top: 120px;
	margin-left: 70px;
	padding-right: 80px;
	width: 90%;
	height: 520px;
}
li{
	list-style-type: none;
}	

